/*
 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */


package java.util.logging;

import java.io.*;
import java.nio.charset.Charset;
import java.util.*;

/**
 * Format a LogRecord into a standard XML format.
 * <p>
 * The DTD specification is provided as Appendix A to the
 * Java Logging APIs specification.
 * <p>
 * The XMLFormatter can be used with arbitrary character encodings,
 * but it is recommended that it normally be used with UTF-8.  The
 * character encoding can be set on the output Handler.
 *
 * @since 1.4
 */

public class XMLFormatter extends Formatter {

  private LogManager manager = LogManager.getLogManager();

  // Append a two digit number.
  private void a2(StringBuilder sb, int x) {
    if (x < 10) {
      sb.append('0');
    }
    sb.append(x);
  }

  // Append the time and date in ISO 8601 format
  private void appendISO8601(StringBuilder sb, long millis) {
    GregorianCalendar cal = new GregorianCalendar();
    cal.setTimeInMillis(millis);
    sb.append(cal.get(Calendar.YEAR));
    sb.append('-');
    a2(sb, cal.get(Calendar.MONTH) + 1);
    sb.append('-');
    a2(sb, cal.get(Calendar.DAY_OF_MONTH));
    sb.append('T');
    a2(sb, cal.get(Calendar.HOUR_OF_DAY));
    sb.append(':');
    a2(sb, cal.get(Calendar.MINUTE));
    sb.append(':');
    a2(sb, cal.get(Calendar.SECOND));
  }

  // Append to the given StringBuilder an escaped version of the
  // given text string where XML special characters have been escaped.
  // For a null string we append "<null>"
  private void escape(StringBuilder sb, String text) {
    if (text == null) {
      text = "<null>";
    }
    for (int i = 0; i < text.length(); i++) {
      char ch = text.charAt(i);
      if (ch == '<') {
        sb.append("&lt;");
      } else if (ch == '>') {
        sb.append("&gt;");
      } else if (ch == '&') {
        sb.append("&amp;");
      } else {
        sb.append(ch);
      }
    }
  }

  /**
   * Format the given message to XML.
   * <p>
   * This method can be overridden in a subclass.
   * It is recommended to use the {@link Formatter#formatMessage}
   * convenience method to localize and format the message field.
   *
   * @param record the log record to be formatted.
   * @return a formatted log record
   */
  public String format(LogRecord record) {
    StringBuilder sb = new StringBuilder(500);
    sb.append("<record>\n");

    sb.append("  <date>");
    appendISO8601(sb, record.getMillis());
    sb.append("</date>\n");

    sb.append("  <millis>");
    sb.append(record.getMillis());
    sb.append("</millis>\n");

    sb.append("  <sequence>");
    sb.append(record.getSequenceNumber());
    sb.append("</sequence>\n");

    String name = record.getLoggerName();
    if (name != null) {
      sb.append("  <logger>");
      escape(sb, name);
      sb.append("</logger>\n");
    }

    sb.append("  <level>");
    escape(sb, record.getLevel().toString());
    sb.append("</level>\n");

    if (record.getSourceClassName() != null) {
      sb.append("  <class>");
      escape(sb, record.getSourceClassName());
      sb.append("</class>\n");
    }

    if (record.getSourceMethodName() != null) {
      sb.append("  <method>");
      escape(sb, record.getSourceMethodName());
      sb.append("</method>\n");
    }

    sb.append("  <thread>");
    sb.append(record.getThreadID());
    sb.append("</thread>\n");

    if (record.getMessage() != null) {
      // Format the message string and its accompanying parameters.
      String message = formatMessage(record);
      sb.append("  <message>");
      escape(sb, message);
      sb.append("</message>");
      sb.append("\n");
    }

    // If the message is being localized, output the key, resource
    // bundle name, and params.
    ResourceBundle bundle = record.getResourceBundle();
    try {
      if (bundle != null && bundle.getString(record.getMessage()) != null) {
        sb.append("  <key>");
        escape(sb, record.getMessage());
        sb.append("</key>\n");
        sb.append("  <catalog>");
        escape(sb, record.getResourceBundleName());
        sb.append("</catalog>\n");
      }
    } catch (Exception ex) {
      // The message is not in the catalog.  Drop through.
    }

    Object parameters[] = record.getParameters();
    //  Check to see if the parameter was not a messagetext format
    //  or was not null or empty
    if (parameters != null && parameters.length != 0
        && record.getMessage().indexOf("{") == -1) {
      for (int i = 0; i < parameters.length; i++) {
        sb.append("  <param>");
        try {
          escape(sb, parameters[i].toString());
        } catch (Exception ex) {
          sb.append("???");
        }
        sb.append("</param>\n");
      }
    }

    if (record.getThrown() != null) {
      // Report on the state of the throwable.
      Throwable th = record.getThrown();
      sb.append("  <exception>\n");
      sb.append("    <message>");
      escape(sb, th.toString());
      sb.append("</message>\n");
      StackTraceElement trace[] = th.getStackTrace();
      for (int i = 0; i < trace.length; i++) {
        StackTraceElement frame = trace[i];
        sb.append("    <frame>\n");
        sb.append("      <class>");
        escape(sb, frame.getClassName());
        sb.append("</class>\n");
        sb.append("      <method>");
        escape(sb, frame.getMethodName());
        sb.append("</method>\n");
        // Check for a line number.
        if (frame.getLineNumber() >= 0) {
          sb.append("      <line>");
          sb.append(frame.getLineNumber());
          sb.append("</line>\n");
        }
        sb.append("    </frame>\n");
      }
      sb.append("  </exception>\n");
    }

    sb.append("</record>\n");
    return sb.toString();
  }

  /**
   * Return the header string for a set of XML formatted records.
   *
   * @param h The target handler (can be null)
   * @return a valid XML string
   */
  public String getHead(Handler h) {
    StringBuilder sb = new StringBuilder();
    String encoding;
    sb.append("<?xml version=\"1.0\"");

    if (h != null) {
      encoding = h.getEncoding();
    } else {
      encoding = null;
    }

    if (encoding == null) {
      // Figure out the default encoding.
      encoding = java.nio.charset.Charset.defaultCharset().name();
    }
    // Try to map the encoding name to a canonical name.
    try {
      Charset cs = Charset.forName(encoding);
      encoding = cs.name();
    } catch (Exception ex) {
      // We hit problems finding a canonical name.
      // Just use the raw encoding name.
    }

    sb.append(" encoding=\"");
    sb.append(encoding);
    sb.append("\"");
    sb.append(" standalone=\"no\"?>\n");
    sb.append("<!DOCTYPE log SYSTEM \"logger.dtd\">\n");
    sb.append("<log>\n");
    return sb.toString();
  }

  /**
   * Return the tail string for a set of XML formatted records.
   *
   * @param h The target handler (can be null)
   * @return a valid XML string
   */
  public String getTail(Handler h) {
    return "</log>\n";
  }
}
